Charles,
Even though the Zotl 40 is a very good amp,
The 2a3 is even more convincing with better natural tone and timbre of instruments and voices and has just a wonderful midrange that isn't too much of a good thing like my Yamamoto is.
I'm gonna save my Yamamoto for my smaller 2nd system and hunt for a speaker that is lean sounding in the mids and I think that will be a better match.
I know that my DI's measure pretty flat with just a small bump up around 500hz,possibly other 300b amps would match better with the DI's for people that need more pwr.
It's been a number of yrs since I owned a 2a3 amp and I guess I forgot how good they can be and with the DI's I do believe I've found a better match for at least 90% of the music I listen too excluding full orchestra.
It just proves to me once again how darn easy the Di speaker is to drive and also how good the little LTA MZ2S preamp is also.
I did change 300b tubes in my Yamamoto to the recommended Eml Xls and it does sound better overall than it ever has but it just has too much midrange bloom for my tastes.
All I can say is Teajay is correct when he has stated numerous times that the low pwr 2a3 amp can rattle his walls and also sounds very good with all kinds of music.
Kenny.